Vat color printing paste



Patented Sept. 26, '1939 2,174,095 VAT coLoa PRINTING PASTE CharlesFranklin Miller, Wilmington, Del., as-

signor to E. I. du Pont de Nemours & Company, Wilmington, Del., acorporation of Delaware No Drawing. Application October 29, 1938, SerialNo. 237,759

4- Claims.

This invention relates to an improved process for printing textilefibers with vat dyes and to dye compositions especially adapted to thisprocess.

More particularly it relates to the preparation and application to afabric composed of either natural or synthetic cellulosic fibers of aprinting composition containing a vat dye and a material adapted tofacilitate the printing operation. The invention also relates to the vatdye color pastes or to vat dye powders and to the fabric imprintedtherewith as articles of manufacture.

It is an object of this invention to provide an improved vat colorprinting paste, which has several distinct advantages over the customaryprinting pastes of this date, especially in respect to stability and tofreedom from speckiness and scumming. Other and further important ob.-jects of this invention will appear as the description proceeds. v

By the term vat dye hereinafter we refer to dyes of the anthraquinone,indigo, and thioindigo series which are generally'applied to the fiberbya reduction process involving the use of alkaline hydjrosulfite or thegroup of formaldehyde-sulfoxy a es.

The printing of fabric with vat colors isa well known and highlydeveloped art. It generally comprises dispersing the vat dye .in athickening paste containing reducing agents, applying to the fabric bymeans of an-engraved roller, then exposing the fabric to the action ofsteam, which is known as ageing, to effect reduction of the colorandfinally treating with a mild oxidizing agent,

and washing and soaping to remove the gum,-un-

fixed color, etc.

Quite-generally, special assistants are added to the dye composition orprinting paste to facilitate the dispersion of the die, prevent dryingout of' the paste, assist penetration of the'printing paste to thereverse side of the fabric, produce greater brilliance in the prints andproduce more level prints on heavily pigmented rayons. But in spite ofall the great advances that have been made in the vat color printingart, many problems remain to confront the printer: among them are thefollowing:

(1) Many vat color printing pastes thicken and become too thick to useafter standing for several days.

(2) Many vat color printing pastes tend to -liver" or separateinto a gumand a water layer on standing, which layers cannot be redispersed.

(3) Many vat color printing pastes tend to agglomerate and give "specky,weak printsif let stand several days. i

v (4) Many vat color printing pastes, particularly those containingspecial assistants to facilitate penetration of the printing paste tothe reverse side of the fabric -and to improve the brilliance andlevelness of the prints on heavily pigmented rayons or spun rayonfabrics, tend to reduce so rapidly either on standing several days or inthe ymer of acetaldehyde; it corresponds to the formula CH3.CHOH.CH2.CHOand is described more fully in Beilstein, 4th ed., Vol. I, page 824. Forthe purpose of this invention, it may be added directly to the printingpaste'as the latter is made up, or it may be incorporated first into, anassistant paste containing the vate dye, with or without supplementalreagents such as penetrating or levelling assistants, which assistantpaste is then incorporated into the thickening paste in the usualmanner, to produce the printing paste.

It is remarkable that acetaldol is unique in the above beneficial effectwith-respect to the problems mentioned, inasmuch as. other aldehydessuch as butyraldehyde and octyl aldehyde of the aliphatic series,sulfo-benzaldehyde, salicyl aldehyde and benzaldehyde of the aromaticseries, and furfural of the heterocyclic series, are either inert in vatcolor printing pastes or else accelerate the thickening, livering andscumming, which are overcome by the use of acetaldol.

The amount of acetaldol necessary to produce the desired effects willvary according to the type of color used; local types of printing pastesemployed'for thickening; and the amount and kind examples are given toillustrate my preferred mode of operation. Parts are by weight.

Pmem'rron or rm: Tmcxamna PASTES Thickening SBG 100 parts of wheatstarch 300 parts of-British gum and 600 parts of water lOOOYparts 7 Thismixture was-pasted to the boil, for 10 min- I utes and cooled to roomtemperature. A smooth paste was obtained.

Thickener A 560 parts of Thickening SBG were heated to 170 F. There werethen added 170 parts of potassium carbonate. After the potassiumcarbonate had dissolved, the paste was cooled to 140 F. and thefollowing ingredients added 120 parts of sodium formaldehyde sulfoxylateparts of glycerine 100 parts of water 1000 parts The whole was thenstirred to form a smooth paste.

Example 1 20 parts of 5,7,5,7-tetrabrom-indigo (c. I. No.

1184) were mixed with 69 parts Thickener A, and to this were added 10parts of a stable emulsion consistingol.

6.0 parts of Turkey red oil 3.2 parts of Assistant A, as defined below0.8 part of benzyl alcohol 10.0 parts and 1 part of acetaldol 100 parts,total (Assistant A consists of a 30% aqueous solution of mixed sodiumalkyl sulfates obtained by the sulfonation of a mixture of CB primaryand C1 secondary monohydric' alcohols (B. P. 133 to 150 C.). Thesecompounds are fully described in United States Patent No. 2,079,788.)

Piece goods variously prepared from lustrous rayon, titanium-dioxidedelustered rayon, and

partially saponified acetate-process rayon, were printed with theprinting composition prepared above, dried, and aged for 5 to 10 minutesat 214 F. in a rapid ager of the Mather-Flatt type. The printed materialwas then treated for '1 minute in an. oxidizing bath at 140 F;containing /g% of sodium bichromate and of acetic acid, rinsed in coldwater, soaped for 5 minutes in a soap bath at 160 F. containing /g% ofsoap,

rinsed and dried.

The above described printing composition does not reduce as rapidly inthe color box of the printing machine or in the printing-paste if .letstand several days as when the printing composition does not contain theacetaldol, and permits a materially longer run to be made withoutscumming. v

Example 2 100 parts of 6,6'-diethoxy-2,2'-bisthionaphthenindigo (C. I.No. 1217) were mixed with 40 parts of Assistant A (as described inExample 1) and 20 parts of Turkey red oil 160 parts, total. There werethen evaporated 65 parts of water, producing 95 parts of assistant colorpaste; to this were added 5 parts of acetaldol, producing 100 parts ofassistant color paste which was run through a colloid mill to secure ahomogeneous mixture. 20 parts of the resulting paste were mixed withparts of Thickener A, as above described,

producing 100 arts, total, of printing paste.

Lustrous rayon piece goods and titanium-dioxide delustered rayon piecegoods were printed with the printing composition described above andfinished as described in the previous example to give a bright, highlypenetrating, level orange 1 print.

The above printing composition can be kept several weeks withoutappreciable thickening, livering or agglomeration and does not reduce asrapidly as similar paste prepared without the acetaldol.

-' Ezrample 3 100 parts of the thioindigoid dye employed in 100 parts ofassistant color paste.

The above composition was thickened as in Example 2, printed on cottonpiece goods and on spun rayon. and finished as in Example 1, giving abright orange printed design.

The above described printing composition can be kept several weekswithout appreciable thickening, "livering, agglomeration or reduction,

whereas a similar composition prepared without the acetaldolagglomerates and gives specky" prints after standing several days.

Example 4 100 parts of the thioindigoid dye mentioned in Example 2 (C.I. No. 1217) were mixed with 20 parts of sodium butyl phthalate (Note A,be-

' low) 120 parts, total. There were then evaporated. 25 parts of water,yielding parts of assistant color paste to which were added 5 parts ofacetaldol, producing parts of assistant color paste which was thenmilled in a. colloid mill to insure a. homogeneous mixture.

20 parts of the last mentioned assistant'color paste were mixed with e80 parts of Thickener A, producing 100' parts of printing paste.

Lustrous, titanium-dioxide-delustered, and partially'saponified acetaterayons were printed with the above composition and finished as inExample 1, giving bright, highly penetrating, very level orange prints.

The above described printing composition can be kept several weekswithout appreciable thickening or agglomeration and does not reduce asrapidly as a. similar paste prepared without the steam distilled toremove the excess alcohol, and

is then evaporated to dryness on the steam bath.

Example 100 parts of the indigoid dye used in Example 1 (C. I. No. 1184)were mixed with 25 parts of sodium-mathyl-pentanol-phthalate (Note A,above) 125 parts, total. There were then evaporated 27 parts oi water,producing 98 parts of color paste, to which were added 2 parts ofacetaldol, producing 100 parts of assistant color paste, which wasmilled in a colloid mill to give a homogeneous mixture.

20 parts 01' the above described assistant color paste were mixed with I80 partsof Thickener A, producing 100 parts of printing paste.

containing the phthalate but no acetaldol, and

has less tendency to "scum in a printing machine.

In the above examples the dyestuii may be re placed by. other vat dyesof the indigoid, thioindigoid or anthraquinone series as for instance:

' Dimcthoxy-dibenzanthrone C. I. No. 1101 3,3'-dichloro-indanthrone C,I. No. 1113 6,6'-dibrorno-4,4' diniethyl -2,2'-

and numerous others.

I claim:

1. A composition of matter for printing textile fiber comprising a vatdyestufl and acetaldol.

2. A composition of matter for printing textile fiber comprising a vatdyes'tufl, a thickening agent, a reducing agent, an alkaline agent, andacetaldol. 5

3. A process of printing cellulosic textile fabric,

. which comprises applying thereto a printing paste comprising a. vatdyestufl, a reducing agent, an alkaline agent, a thickening agentand'acetaldol.

4. A process of printing cellulosic textile fabric, which comprisesapplying thereto aprinting paste comprising a vat dyestuit, sodiumformaldehyde sulfoxylate, potassium carbonate, starch- British gumthickening, and acetaldol, the quantityof acetaldol being from V to 2%by weight of the entire compositions and then subjecting the fabric tosteam ageing, oxidation and soaping'

